US3064945A - Weight lifting and supporting mechanism - Google Patents

Description

Nov. 20, 1962 R. A. FORBES WEIGHT LIFTING AND SUPPORTING MECHANISM 2 Sheets-Sheet 1 Filed Aug. 19, 1959 m T m m ROBERT A.FORBES 5%a/we'1 S' 1-- ATTORNEYS Nov. 20, 1962 R. A. FORBES 3,

WEIGHT LIFTING AND SUPPORTING MECHANISM Filed Aug. 19, 1959 2 Sheets-Sheet 2 59 i ii 66 6 fi H FIG.7. 59 i:

INVENTOR. ROBERT A F ORBES ATTORNEYS 3,%4,945 Patented Nov. 2%, 1982 3,064,945 WEIGHT LIFTING AND SUPPORTING MECHANISM Robert A. Forbes, 2031 Miles Ave., Toledo 6, Ohio Filed Aug. 19, 1959, Ser. No. 834,849 6 Claims. (Cl. 254-107) This invention relates to lifting, supporting and lowering devices.

An object of this invention is to provide, lifting, supporting, and lowering devices, such as automobile jacks, adapted to lift heavy objects.

Another object of this invention is to provide a device of the above character which is dependable, strong, light in weight and adapted for manufacture at low cost.

Another object of this invention is to provide in a lifting, supporting and lowering device, anchoring means adapted to hold a smooth elongate tensioned lift member against movement in response to the tension load thereon.

Another object of this invention is to provide means adapted to hold a smooth elongate member against longitudinal movement in one direction relative thereto while allowing free longitudinal movement in the opposite direction.

A further object of this invention is to provide means for securing a longitudinally shiftable elongate member against relative movement in one direction but allowing substantially free movement thereof in the opposite direction, the means tending to rotate about an axis extending transversely of the line of shifting of the elongate member.

Another object of this invention is to provide a device of the above character which serves to effect lifting in an incremental, that is a step-by-step fashion, in which the increments or steps may vary in dimension within a size range from zero to a predetermined maximum length, without any substantial baek-slipping from the respective, successive maximum elevations attained through each successive upward lift movement.

Another object of this invention is to provide a lifting, supporting and lowering device, means adapted to hold a smooth, elongate lift member against longitudinal movement in one direction relative thereto, while allowing free longitudinal movement thereof in the opposite direction.

Another object of this invention is to provide in lifting, supporting, and lowering devices, means for securing a longitudinally shiftable elongate lift member against relative movement in one direction but allowing free longitudinal movement thereof in the opposite direction, said securing means tending to rotate about an axis extending transversely of the elongate lift member.

A further object of this invention is to provide a de vice in which a pair of securing means are provided in cooperative relation to an elongate lift member, one of said pair of securing means securing said elongate lift member against longitudinal movement in one direction, and the other of said pair being movable and adapted to shift said elongate lift member in the opposite direction.

The above and other features and objects of this invention will in part be obvious and will in part be apparent to those having ordinary skill in the art to which this invention pertains, from the accompanying description and drawings.

In the drawings:

FIGURE 1 is a view in side elevation of an embodiment of the invention in a bumper jack, portions thereof having been broken away to show details of construction and to shorten the heighth of the view;

FIG. 2 is a view in rear elevation of the device shown in FIG. 1, portions thereof having been broken away to show details of construction and to shorten the height of the view;

FIG. 3 is a fragmentary view in side elevation, partly in section, taken generally along the line 3-3 in FIG. 2, parts being shown in relative positions corresponding to the beginning of a lift stroke;

FIG. 4 is a fragmentary view, similar to FIG. 3, but in which the parts shown are in relative position corresponding to the finish or upper end of a lift stroke;

FIG. 5 is a fragmentary view in section taken along the line 55 in FIG. 2, the parts being shown in relative positions corresponding to FIG. 3;

FIG. 6 is a fragmentary view in section taken along the line 5-5 in FIG. 2, the parts being shown in altered relative positions corresponding to FIG. 4;

FIG. 7 is a fragmentary view in section taken along the line 7-7 in FIG. 2; and

FIG. 8 is a fragmentary view in section taken along the line 88 in FIG. 2.

In the specification and drawings, like reference characters indicate like parts.

The illustrative embodiment of the device shown in the drawings is an automobile bumper jack 15 The jack 15 comprises a base plate 16 secured to a standard rootreceiving socket 17, as shown in FIG. 1. The base plate 16 may be a sheet metal stamping of generally pyramidal shape and the socket a stamping or forging adapted to cooperatively receive the root portion 19 of jack standard 18. The central portion of standard 18 which extends upwardly from root portion 19 is a hollow member having a longitudinal slot 20 (FIG. 2) and a horizontal sec tion of generally C-shape. A pair of integral arms 21 and 22 extend symmetrically upwardly from the central portion of standard 18 in spaced relation as shown most clearly in FIG. 2. A cap plate 23 is secured in cooperating relation to the upper end portions of arms 21, 22 by any suitable means, such as welds, or the like. Cap plate 23 serves to support the upper end portions of arms 21 and 22 against alteration in the spacing thereof, while the arms serve to support plate 23 in fixed relation to the remainder of standard 18. As shown most clearly in FIG. 2, a generally channel-shaped portion 24 is an integral portion of standard 18. Portion 24 serves as a gusset or reinforcing plate between the lower portions of arms 21, 22 and the central portion of the standard 18, while also serving to provide a pair of parallel plate-like arm portions 25, 26 in spaced, parallel relation to each other and the arms 21, 22.

The standard 18, that is, root 19, arms 21, 22, cap plate 23, and channel-shaped portion 24 which includes plate-like arm portions 25, and 26, are joined together to form a unitary, strong structure.

Aligned apertures are provided in arms 21, 22 and platelike arm portions 25, 26 through which pivot shaft 27 extends as shown in FIG. 2. Pivot shaft 27, as shown, may be in the form of a post-bolt having adjacent its respective ends a head 23 and a threaded portion adapted for threaded cooperation with nut 29. Portions 21, 22, 25 and 26 of standard 13 thus serve to support pivot shaft 27 while the head 28 and nut 29 thereof permit it to provide lateral support for portions 21, 22. Shaft 27 is thus supported in fixed relation to standard 18. As shown most clearly in FIG. 1, a slot 30 is provided in arm 21 and a duplicate slot 31 is provided in corresponding position in arm 22. Movable pivot shaft 32 extends through slots 30 and 31 in parallel, spaced relation to pivot shaft 27. Movable pivot shaft 32 has a head 33 and is in cooperative, threaded engagement with nut 34. Head 33 and nut 34 are so spaced as to offer little or no frictional resistance to movement of movable pivot shaft 32 along slots 30, 31 toward or away from pivot shaft 27 in parallel relationthereto. Slots '30 and 31 are of equal length and serve to establish maximum and minimum limits on the spacing of shafts 32 and 27 As shown most clearly in FIGS. 2, 3 and 4, a pair of parallel link members 40, 41 are respectively secured in pivotal relation to pivot shaft 27 between cooperating shaft supports 21 and 25, and 22 and 26. While each link member 40, 41 adjacent one respective end thereof is pivotally secured to shaft 27, it is also pivotally secured adjacent its second end to rocker lever 42 by rocker shaft 43. Rocker lever 42 has a pair of yoke arms 44, 45 through apertures in which rocker shaft 43 extends. Arms 44, 45 are joined by a central sleeve-like portion 47 adapted to cooperate with lever extension 46, a portion of which is shown in FIG. 1, such as a combination automobile wheel cover removing tool and lug wrench. The movable pivot shaft 32 extends through apertures provided in arms 44, 45. As lever 42 is rocked about rocker shaft 43, shaft 32 is moved up and down in slots 30, 31 and remains parallel to shaft 27. The length of slots 30, 31 determines the amplitude of swinging or rocking of lever 42 through cooperation of shaft 32 with the slot-bounding portions of arms 21, 22 and 44, 45. Further, the slots 30, 31 as shown and previously described, are straight. As lever 42 swings or rocks about rocker shaft 43, the latter moves toward and away from the slots. That is, rocker shaft 43 is supported by link members 40, 41 which pivot on shaft 27, so as to swing in response to rocking of lever 42 in cooperative relation to movable shaft 32, which in turn extends through the guide slots 30, 31. Thus, clockwise rocking or swinging of lever 42 as viewed in FIG. 1, will serve to shift or move movable pivot shaft 32 toward the upper end of the slots, and counter-clockwise movement of the lever following such clockwise movement, would serve to advance movable pivot shaft .32 downwardly toward the limit position in which it is shown in FIG. 1. The upward movement of shaft 32 from the position in Which it is shown in FIGS. 1, 2, 3, and 5, is accompanied by swinging or pivoting of link members 40, 41 in a clockwise direction, shifting rocker shaft 43 to the right of the position in which it is shown in FIGS. 1 and 3, as movable shaft 32 is raised to a position in which it and rocker shaft 43 are equally elevated above pivot shaft 27. Further, clockwise rocking of lever 42 about rocker shaft 43 effects further elevation of movable pivot shaft 32 relative to pivot shaft 27 and such further upward movement of shaft 32 is accompanied by counterclockwise pivoting or swinging of link members 40, 41, and as a result, rocker shaft 43 is shifted to the left toward the position in which it is shown in FIGS. 4 and 6.

A lower or holding securing means 50 cooperating with pivot shaft 27, and a similar upper or lifting securing means 70 cooperating with movable pivot shaft 32, are provided and each is adapted to cooperate with lift rod 35, as described subsequently herein. Lift member 35 may, as shown, he an elongate, smooth surfaced, cylindrical rod which extends through a guide in cap plate 23 and extends parallel to and partly in slot 20. Rod 35 also extends through the shank 36 of automobile bumper engaging hook 37 and stop collar 38. Collar 38 may be a separate member secured to rod 35 by welding or any suitable means, not shown, or it (38) may be an integral shoulder or head on rod 35. As shown, hook 37 is secured to shank 36 and adapted to engage an automobile bumper 39 so as to tend to remain in fixed relation to the bumper in order that forces transmitted through hook 37, shank 36 and collar 38 to cooperating lift rod 35 are directed lengthwise of that rod. Thus, upward movement of lift rod 35 from the position shown in FIG. 1 will effect lifting of bumper 39 and hook 37 in unison therewith. Shoulder or stop collar 68 is secured to rod 35 by means such as screw 69 and serves to cooperate with cap plate 23 to limit movement of rod 35 in the direction indicated by arrow B in FIG. 6.

The lower or holding securing means 50 comprises an inverted channel-shaped frame 51. An aperture 53 is provided in web portion 52 of frame 51 and is slightly larger than the cross section of lift rod 35 which extends through that aperture; A pair of spaced parallel flanges 54 extend downwardly from web 52, respectively, on opposite sides of rod 35. A tie member 55 extends between and is secured adjacent its ends to flanges 54, in spaced relation to lift rod 35. A pair ofslots 56, shown in FIGS. 7 and 8, are provided in flanges 54 through which pivot shaft 27 extends. Slots 56 are oriented so that their center lines lie in a common plane. As will be apparent from FIG. 7, the common plane of the slot center lines, extends obliquely downwardly from a radial plane of lift rod 35 through the axis of pivot shaft 27. The slots 56, the member 55 and aperture 53 are so positioned that frame 51 tends to pivot about shaft 27 in a counterclockwise direction as viewed in FIGS. 1, 3, 4, 5, 6, and 7. Thus, frame 51 tends to rest against lift rod 35 at '57 and also to slide toward a position in which pivot shaft 27 is advanced toward web 52. As shown in FIGS. 2, 3, 4, 5, 6, and 7, a rest 58 hangs on pivot shaft 27 between flanges 54. Rest 58 has a complementary face adapted to rest against lift rod 35 and serves to establish the minimum spacing distance of pivot shaft 27 from lift rod 35. Rest 58 pivots on shaft 27 to adjust to the position in which it lies in face-to-face relation to rod 35. A hanger bar 59 is provided, having adjacent one of its ends a guide aperture 60 through which lift rod 35 extends. Adjacent its end remote from lift rod 35, hanger bar 59 rests on tiemember 55 and as a result tends to gravitationally rock or pivot in a clockwise direction about tie member 55 as viewed in FIGS. 1, 3, 4, 5, 6, and 7. Such rocking or pivoting is limited by cooperation between lift rod 35 and the surface of bar 59 defining aperture 60. A second aperture 61 is provided in bar 59 between aperture 60 and the place of its contact with tie member 55. Aperture 61 as shown may be frusto-conic or of any shape which will permit some swinging of hanger link 62 extending downwardly therethrough. Spacing member 63 is suspended beneath hanger bar 59 by hanger link 62. Spacing member 63 has a central aperture 64, which, like aperture 61, is shaped to allow some swinging of hanger link 62 therein. Hanger link 62 has heads 65, 66 which respectively cooperate with hanger bar 59 and spacing member 63 to suspend spacing member 63 below bar 59 between tie member 55 and lift rod 35.

As previously explained, frame 51, at 57, tends to remain in contact with, that is ride against, lift rod 35 at all times. Gravitational forces tend to rotate and shift the position of frame 51 relative to lift rod 35 so as to bias tie member 55 into contact with spacing member 63 and the latter in turn to ride against rod 35. Gravitational forces also tend to move web portion 52 toward pivot shaft 27 and cooperation of the latter in slots 56 also tends to move frame 51 relative to red 35 so that tie member 55 in contact with spacing member 63 urges the latter against lift rod 35. Thus lower or holding securing means tends to move toward securing relation to rod 35 under gravitational forces. Slight opposite movements of the parts of lower securing means 5% occur in response to slight upward movement of lift rod 35, that is, in the direction of arrow A in FIG. 5, as to permit the rod 35 to move through securing means 50 with only slight drag thereon from the means 50. However, a very slight, almost imperceptible motion of rod 35 in the direction opposite to that indicated by arrow A, that is, in a downward direction, results in setting of securing means 50 into firm, securing relation to the rod 35. Securing means 5%}, as previously explained, is supported on pivot shaft 27 and so when set, holds rod 35 against downward movement, that is, in fixed relation to standard 13. The greater the downwardly acting load imposed upon rod 35 through hook 37, the more tightly lower or holding securing means 50 sets. While securing means 5%) releases in response to very slight, almost imperceptible, upward movement of rod 35, it remains in cooperating relation to the rod and will set in response to very slight, almost imperceptible downward movement of rod 35 after any amount of upward movement of rod 35.

Lower or holding securing means 50 may be unset or released to permit lowering of lift rod 35 through the use of a lever 67 as is illustrated in HS. 7. The lever 67 is fulcrumed upon the upper edge 2% of channel-shaped portion 24 which is an integral portion of the standard 13. The lever 67 may be a screw driver as shown, or the hub cap removing end portion of the combination lug wrench and hub cap removing tool, which, as previously explained, may be used as lever extension 46. The lever 67, as illustrated in FIG. 7, when fulcrumed on channelshaped portion 24 may be used to raise hanger bar 59 into engagement with the underside of web 52 of frame 51 and through it frame 51, as well. If this releasing operation is performed carefully, it is possible to effect partial releasing in a manner such that securing means 5t serves as a drag brake on lift rod 35 and thus retards the speed at which rod 35 moves downwardly.

The upper or lifting securing means 79 comprises an inverted channel-shaped frame 71 having a web portion 72 joining two flange portions 74. An aperture 73 is provided in web portion 72 of frame 71 and is slightly larger than the cross section of lift rod 35 which extends through that aperture. A pair of spaced parallel flanges 74 extend downwardly from web 72, respectively, on opposite sides of rod 35 and spaced therefrom. A tie member 75 extends between and is secured adjacent its ends to flanges 74 in spaced relation to lift rod 35. A pair of slots 76 are provided in flanges 74 through which movable pivot shaft 32 extends. Slots 76 are oriented so that their center lines lie in a common plane. As will be apparent from FIG. 6, the common plane of the slot 76 center lines, extends obliquely downwardly from a transverse radial plane of lift rod 35 through the axis of movable pivot shaft 32. The slots 76, the tie member 75 and aperture 73 are so positioned that frame 71 tends to pivot about shaft 32 in a counter clockwise direction, as viewed in FIGS. 1, 3, 4, 5, and 6. Thus frame 71 tends to rest against lift rod 35 at 77 and also to slide toward a position in which movable pivot shaft 32 is advanced toward web 72. As shown in FIGS. 2, 3, 4, 5, and 6, a rest 73 hangs on pivot shaft 32 between flanges 74. Rest 78 has a complementary face adapted to rest against lift rod 35 and serves to establish the minimum spacing of movable pivot shaft 32 and lift rod 35. Rest 78 pivots on shaft 32 to adjust to the position in which it lies in faceto-face relation to rod 35. A hanger bar 79 is provided, having adjacent one of its ends a guide aperture 89 through which lift rod 35 extends. Adjacent its ends, remote from lift rod 35, hanger bar 79 rests on tie member 75, and, as a result, tends to gravitationally rock or pivot in a clockwise direction about tie member 75 as viewed in FIGS. 1, 3, 4, 5, and 6. Such rocking or pivoting is limited by cooperation between lift rod 35 and the surface of bar 79 defining aperture 84}. A second aperture 31 is provided in hanger bar '79 between aperture 80 and the place of its contact with tie member 75. Aperture 31, as shown, may be frusto-conic, or of any shape that will permit some swinging of hanger link 82 extending downwardly therethrough. Spacing member 83 is suspended beneath hanger bar 79 by hanger link 82. Spacing member 83 has a central aperture 34, which, like aperture 81, is shaped to allow some swinging of hanger link 82 therein. Hanger link 82 has heads 85, 86, which respectively cooperate with hanger bar 79 and spacing member 83 to suspend spacing member 83 between tie member 75 and lift rod 35 and below bar 79. Frame 71 at 77 tends to remain in contact with, that is, ride against, lift rod 35 at all times. Gravitational forces tend to rotate and shift the position of frame 71 relative to lift rod 35 so as to bias tie member 75 into contact with spacing member 33 and the latter in turn to ride against rod 35. Gravitational forces also tend to move web portion 72 toward movable pivot shaft 32 and cooperation of the latter in slots 76 also tends to move frame 71 relative to rod 35 so that tie member 75 in contact with spacing member 83 urges the latter against lift rod 35. Hanger bar 79 adjacent one end rests upon frame member 75 and adjacent its other end surrounds a portion of lift rod disposed in guide aperture 35. As viewed in FIGS. 5 and 6, hanger bar 79 tends to swing about tie member 75 in a clockwise direction and thus tends to cooperate with lift rod 35 so that movement of tie-memher 75 and hanger bar 79 from the position shown in FiG. 5 upwardly in the direction of arrow A, will result in cooperation of bar 79 with lift rod 35 to produce a force acting upon tie-member 75 in a direction opposite to that indicated by arrow A. (That is, some force tending to lift rod 35 is applied by tie-member 75 to hanger bar 79.) Such cooperation results in an opposite force acting in concert with the gravitational force and increasing the tendency of frame 71 to shift in the direction above described to secure upper or lifting securing means '70 in relation to lift rod 35, such that further upward movement of the securing means 70 in the direction of arrow A results in equal upward movement of lift rod 35.

The lower or holding securing means 51) holds lift rod 35 against downward movement, that is, in the direction of arrow B, but offers virtually no resistance to its movement in the direction of arrow A. Upper or lifting securing means 7t) is coupled to lever 42 by movable pivot shaft 32 which shaft is guided by slots 36, 31, so as to move in constant-distance spaced relation to rod 35. Securing means 70 holds lift rod 35 securely when the latter tends to move in the direction of arrow B relative to securing means 70, except when securing means 73 is in the position in which it is shown in FIGS. 3 and 5. There, securing means 71 is in its lowest position and hanger bar 73 rests on rocker shaft 43 at 49 after being swung slightly in a counter-clockwise direction about tiemember 75 through cooperation with shaft 43. This slight, almost imperceptible movement, reduces cooperation between hanger bar 79 and rod 35 to the level at which rod 35 will slide freely through securing means 76 in the direction of arrow B.

The jack 15 illustrated, may be operated to lift an automobile in the following manner. Rod 35 may be grasped in the vicinity of shoulder or stop collar 63 and drawn upwardly by hand in the direction of arrow A until bumper hook 37 engages bumper 39 as shown in PEG. 1.

Such hand movement of rod 35 is possible as both securing means 50 and 76 release in response to such move ment of rod 35. Lever extension is placed in cooperative engagement with lever 47. and swung downwardly in a clockwise direction from the position shown in FIGS. 1, 2, 3, and 5 toward the position shown in FIGS. 4 and 6, to raise securing means 7t). While securing means 73 is rising it holds rod 35 securely and lifts rod 35, bumper hook 37 and bumper 39 upwardly in unison with it. The downward swing of lever 4-3 with extension 43 may be a full stroke which results in raising of movable pivot shaft 32 to the upper ends of slots 3t), 31, or a shorter stroke as desired. The first portion of the downward stroke of the lever 42 from the position shown in FIGS. 1, 2, 3, and 5, is very small and results in disengagement of hanger bar 79 from rocker shaft 43 to allow securing means 75 to move into cooperative relation to lift rod 35 so that slight further movement of the lever in the same direction places the securing means 75 in holding relation to lift rod 35. Further swinging of the lever 42 and extension 46 effects unison movement of rod 35 and securing means 70. After the lever 42 has been swung in a clockwise direction, as viewed in PEG. 1, to the end of the stroke desired, it may be swung in a counter-clockwise or upward direction through a return storke. As the return stroke is commenced lift rod 35 tends to move downwardly in the direction of arrow B, which movement is almost imperceptible and which movement places securing means in holding relation to rod 35 to prevent further downward movement thereof. When downward movement of rod 35 is so precluded, securing means releases to slide freely in the direction of arrow B along rod 35 toward securing means as lever 42 moves in a counterclockwise direction. If lever 52 is moved to the position shown in FIG. 1, then the succeeding downward or lifting stroke of the lever will include an initial phase in which hanger bar 79 is disengaged from rock lever 43 as previously explained, because the latter two mentioned members were placed in cooperation by the concluding phase of the return stroke. However, if the return stroke, counter-clockwise movement of lever 42 as viewed in PEG. 1, is terminated before hanger bar 79 engages rocker shaft 43, reversal in the direction of lever movement, that is, movement of the lever in a clockwise direction as viewed in FIG. 1, will result in securing means 7 3 assuming a holding relation to lift rod after only the slightest clockwise movement of lever 42. Further clockwise movement of lever 42 moves securing means 7% upward and with it lift rod 35. Upward movement of lift rod 35 of course causes securing means to release same, to move freely upwardly while securing means 50 remains in an attitude such that the slightest downward movement of lift rod will result in secure holding of same by securing means Sit. Repeated manipulation of lever 42 in alternating clockwise and counter-clockwise move ments, effects step-by-step upward advancement of lift rod 35 until bumper hook 37 has raised bumper 3? the distance desired. When bumper 39 has been raised to the elevation desired, lever 42 and extension 46 may be released, that is, the operators hand may be removed and same will remain stationary as securing means 5% precludes downward movement of rod 35.

The automobile may be lowered by placing a lever, as shown in FIG. 7, that is, fulcrumed upon edge 24-2 of channel-shaped portion 24 so as to pry hanger bar 59 upwardly to release the hold of securing means 50 on lift rod 35 to the extent that rod 35 slides downwardly, in the direction of arrow B. If the prying forces are applied with care, the rate of descent may be slowed by braking action of securing means Stl. If securing means 7% is in any position other than that in which it is shown in FIGS. 1, 2, 3, and 5, it will move downwardly into that position in which its hold on lift rod 35 is released by cooperation of hanger bar 59 with rocker shaft 43.

Having thus described what appears to be a preferred embodiment of the instant invention, it will be apparent to those having ordinary skill in the art to which this invention pertains, that various modifications and changes may be made in the disclosed embodiment, without de parting from either the spirit or the scope of the invention.

Therefore, what is claimed as new and is desired to be secured by Letters Patent is:

l. A jack which comprises a base, an upright standard supported on said base, a transverse shaft mounted in and extending transversely of said standard, a link member pivotally mounted on said transverse shaft, a rocker lever pivotally mounted on said link member, a pivot shaft mounted on said rocker lever parallel to the transverse shaft and movable lengthwise of the standard, there being a guide in said standard guiding the pivot shaft for movement lengthwise of the standard toward and away from the transverse shaft, a lift rod mounted in said standard for movement therealong, a hanger bar extending transversely of the lift rod and having an enlongated guide aperture through which the lift rod extends, a spacer bar linked to and hanging below the hanger bar and extending normally to the lift rod, a stop frame mounted on the transverse shaft for swinging thereabout, a stop member carried by the stop frame and engageable by the underside of the hanger bar, the spacer bar spanning the space between the stop member and the lift rod to limit swinging of the stop frame in one direction, and means mounted on the transverse shaft engageable with the lift rod to limit swinging of the stop frame in the opposite direction, the hanger bar engagin the lift rod at the aperture when the lift rod moves downwardly so that the hanger bar engages the stop member to swing the stop frame in a direction to cause engagement of the spacer bar between the lift rod and the stop member to lock the lift rod against the downward movement, the hanger bar being raised when the lift rod is raised to release the spacer bar, and means carried by the pivot shaft for engaging the lift rod when the pivot shaft is raised to lift the lift rod when the pivot rod is raised, the spacer bar gripping the lift rod when the pivot shaft is lowered.

2. In a load supporting device the combination comprising a standard, a smooth elongate member longitudinally movable relative to said standard, at least two members on opposite sides of the elongate member and engageable with said elongate member, said two members being pivotally supported with reference to said standard, means connecting and biasing said two men"- bers toward engagement with said elongate member and including a member movable relative to said standard to advance one of said two members toward the other to grip the elongate member in response to longitudinal movement of said elongate member in a predetermined direction while in engagement with said two members, whereby said elongate member may be secured against longitudinal movement in said predetermined direction relative to said standard.

3. In a load supporting mechanism the combination comprising an elongate load carrying member tending to move in a predetermined lengthwise direction under load applied force, a support member, a pair of movable members pivotally supported on opposite sides of said load carrying member and engageable with said load carrying member, means connecting said pair of movable members and biasing them toward engagement with said elongate load carrying member and including a member movable to advance one of said two members toward the other to grip the elongate member in response to longitudinal movement of said elongate member in a predetermined direction while in engagement with said two members, whereby lengthwise movement of said load carrying member in said predetermined direction in response to load applied forces cooperatively moves said pair of movable members toward each other to secure said load carrying member against further lengthwise movement relative to said support member in response to load applied forces, and said pair of movable mem bers being moved to release said load carrying member incident to lengthwise movement of the load carrying member in a direction opposite to that in which load applied forces tend to move same.

4. In a load supporting device having a smooth elongate member tending to move longitudinally in one direction under and with a supported load, the combination comprising a frame engageable with and extending on opposite sides of said elongate member and having slots extending in non-parallel relation to said elongate member, a support member, a supporting pivot on said support member and extending through said slots in said frame and supporting same and having an axis extending transversely of the line of longitudinal movement of said elongate member, a rest pivotally supported on said supporting pivot for engaging said elongate member, a spacing member supported on said frame and engageable with the elongate member, said rest and said spacing member being located on opposite sides of said elongate member, said frame tending to shift longitudinally of the center line of said slots and rotate about said pivot and remain in cooperative relation to said elongate member for biasing said rest and spacing member toward cooperative relation with said elongate member, longitudinal movement of said elongate member under a supported load tending to rotate said frame about its pivot axis, the frame, rest, and spacing member engaging and the rest and spacing member grippingly securing said elongate member against movement in the direction it is urged by said lead.

5. in a load supporting device having a smooth elongate member tending to move longitudinally in one direction under and with a supported load, the combination comprising a frame mounted on and extending on opposite sides of said elongate member and having slots extending in non-parallel relation to said elongate member, a support member, a supporting pivot on said support member and extending through said slots in said frame and supporting same and having an axis extending transversely of the line of longitudinal movement of said elongate member, a rest pivotally supported on said supporting pivot for engaging said elongate member, a spacing member supported on said frame and engageable with the elongate member, said rest and said spacing member being located on opposite sides of said elongate member, said frame tending to shift longitudinally of the center line of said slots and rotate about said pivot and remain in cooperative relation to said elongate member for biasing said rest and spacing member toward cooperative relation with said elongate member, longitudinal movement of said elongate member under a supported load tending to rotate said frame about its pivot axis, the frame, rest, and spacing member engaging and the rest and spacing member grippingly securing said elongate member against movement in the direction it is urged by said load.

6. In a load supporting device the combination comprising a smooth elongate member tending to move longitudinally in one direction under and with a supported load, a standard, a frame mounted on and extending transversely of and on opposite sides of said elongate member and having slots extending in non-paral el relation to said elongate member, a pivot extending through said slots and supporting said frame on said standard and having an axis extending transversely of the line of longitudinal movement of said elongate member, a rest pivotaliy supported on said pivot for engaging said elongate member, a spacing member supported on said frame and engageable With said elongate member, said rest and said spacing member being located on opposite sides of said elongate member, said frame tending to shift longitudinally of the center line of said slots and rotate about said pivot and remain in cooperative relation to said elongate member for biasing said rest and spacing member toward cooperative relation with said elongate member, longitudinal movement of said elongate member under a supported load tending to rotate said frame about its pivot axis, the frame, rest, and spacing member engaging and the rest and spacing member grippingly securing said elongate member against movement in the direction it is urged by said load.

References Cited in the file of this patent UNITED STATES PATENTS 305,392 Joyce Sept. 16, 1884 346,783 Stanford Aug. 3, 1886 346,784 Stanford Aug. 3, 1886 824,614 Beaver June 26, 1906 1,349,576 Markham Aug. 17, 1920 1,372,005 Brandt Mar. 22, 1921 2,601,230 Shobe June 24, 1952

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